Gas Gauge...I give up...

My gas gauge doesn't work at all in my 70 Dart, never has. The gas gauge not working seems like a minimal problem, definitely not one to sell your car over.
Also doesn't work in my 75 Ford, and with the 390 4bbl, I sure wish it did work!
Also only works half the time in my 65 Valiant, and it's a daily driver.